I was asked to block pings from the internet to the outside interface of our ASA-5505 firewall. I found a post that said to enter "icmp deny any outside", however that does not do it.
I created an ACL to try and do the trick, also to no avail:
access-list outside_in extended permit icmp any any echo-reply
access-list outside_in in interface outside
access-group outside_in in interface outside
Anyone have a clue what I'm doing wrong? I'm not the firewall guy as you can tell.
Thanks in advance...
Block / Deny ICMP Echo (Ping) on Cisco ASA Outside Interface
Most networks that you protect with a Cisco ASA device, will probably want to deny ICMP (maybe not all ICMP types, but a lot of network admins will want to block ICMP Echo, etc.) on the outside interface. This will make the network harder to find through external enumeration, but not impossible.
ASA5505(config)#icmp deny any outside
You will deny ICMP on the outside interface, but if you include ICMP as a protocol in the default global policy map, you can ping from the inside to any host on the outside, and it will be permitted back through the ASA, as it knows about the previous ICMP “connection
